An effort was made to determine what factors are responsible for
differences in color quality between preserves commercially manufactured
from Hood and Tioga strawberry varieties.
Color analyses made on Hood and Tioga preserves, during a 26 week
storage period, included spectral measurements of aqueous extracts
from the preserve samples. In addition, Hunter color coordinates were
determined for both the insoluble residues (remaining after extraction)
and the intact preserve samples. Color analyses revealed that color
deterioration occurred at a much faster rate in Tioga preserves than
in Hood preserves, and that this deterioration was due to a faster rate
of browning in Tioga preserves.
Complete chemical analyses of fruit revealed striking compositional
differences between Hood and Tioga varieties. The concentrations of
free amino acids and metal ions were found to be similar in both varieties.
Ascorbic acid, which is believed by many to contribute significantly
to color deterioration, was actually present in lower concentration
in the Tioga variety. Anthocyanins were present in greater amounts in the Hood variety, while leucoanthocyanins, flavanols and total
phenolics were higher in Tiogas. Recent work, primarily with wine
and model wine systems, has shown that leucoanthocyanins, catechins,
and possibly other reactive phenolics, will react with anthocyanins to
form polymeric pigments. The results of this study are supportive of
the hypothesis that a similar reaction in preserves (between anthocyanins
and other phenolics) is responsible for color deterioration during
storage. / Graduation date: 1978
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27296 |
| Date | 16 June 1977 |
| Creators | Abers, Julie Ellen |
| Contributors | Wrolstad, R. E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
Page generated in 0.0021 seconds